Context.— Hospitals that treat a relatively high volume of patients for selected
surgical oncology procedures report lower surgical in-hospital mortality rates
than hospitals with a low volume of the procedures, but the reports do not
take into account length of stay or adjust for case mix.
Objective.— To determine whether hospital volume was inversely associated with 30-day
operative mortality, after adjusting for case mix.
Design and Setting.— Retrospective cohort study using the Surveillance, Epidemiology, and
End Results (SEER)–Medicare linked database in which the hypothesis
was prospectively specified. Surgeons determined in advance the surgical oncology
procedures for which the experience of treating a larger volume of patients
was most likely to lead to the knowledge or technical expertise that might
offset surgical fatalities.
Patients.— All 5013 patients in the SEER registry aged 65 years or older at cancer
diagnosis who underwent pancreatectomy, esophagectomy, pneumonectomy, liver
resection, or pelvic exenteration, using incident cancers of the pancreas,
esophagus, lung, colon, and rectum, and various genitourinary cancers diagnosed
between 1984 and 1993.
Main Outcome Measure.— Thirty-day mortality in relation to procedure volume, adjusted for comorbidity,
patient age, and cancer stage.
Results.— Higher volume was linked with lower mortality for pancreatectomy (P=.004), esophagectomy (P<.001),
liver resection (P=.04), and pelvic exenteration
(P=.04), but not for pneumonectomy (P=.32). The most striking results were for esophagectomy, for which
the operative mortality rose to 17.3% in low-volume hospitals, compared with
3.4% in high-volume hospitals, and for pancreatectomy, for which the corresponding
rates were 12.9% vs 5.8%. Adjustments for case mix and other patient factors
did not change the finding that low volume was strongly associated with excess
Conclusions.— These data support the hypothesis that when complex surgical oncologic
procedures are provided by surgical teams in hospitals with specialty expertise,
mortality rates are lower.